Image processing apparatus, image processing method, and electronic apparatus

ABSTRACT

The present technology relates to an image processing apparatus, an image processing method, and an electronic apparatus that make it possible to suppress, where a pixel signal of a large pixel and a pixel signal of a small pixel are composed to generate a WD image, degradation of image quality of the WD image. An image processing apparatus includes a first acquisition unit that acquires a first pixel signal output from a first pixel, a second acquisition unit that acquires a second pixel signal output from a second pixel having a size smaller than that of the first pixel, a temperature detection unit that detects temperature, a composition gain determination unit that determines a composition gain corresponding to the detected temperature, and a composition unit that composes the first pixel signal and the second pixel signal multiplied by the composition gain.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2018/010162 filed on Mar. 15, 2018, which claimspriority benefit of Japanese Patent Application No. JP 2017-062306 filedin the Japan Patent Office on Mar. 28, 2017. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present technology relates to an image processing apparatus, animage processing method, and an electronic apparatus, and particularlyto an image processing apparatus, an image processing method, and anelectronic apparatus that compose pixel signals output from pixelshaving different light reception sensitivities to generate a WD (widedynamic range) image.

BACKGROUND ART

As a method of generating a WD image, a method of providing a firstpixel and a second pixel having different sensitivities on a pixel arraysuch as a CMOS (complementary metal-oxide semiconductor) image sensorand composing outputs of the pixels, i.e., a first image and a secondimage has been known.

Here, examples of providing pixels having different sensitivitiesinclude a method of providing a pixel having a long exposure time(hereinafter, referred to as long accumulation pixel) and a pixel havinga short exposure time (hereinafter, referred to as short accumulationpixel) and a method of providing a pixel that includes a photoelectricconversion unit such as a PD (photodiode) having a large size(hereinafter, referred to as large pixel) and a pixel that includes aphotoelectric conversion unit such as a PD having a small size(hereinafter, referred to as small pixel) (see, for example, PatentLiterature 1).

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Application Laid-open No.2004-222154

DISCLOSURE OF INVENTION Technical Problem

In the method of providing the long accumulation pixel and the shortaccumulation pixel, both the pixel have the same structure, and variouscharacteristics that can depend on the temperature of both pixels arecommon. Therefore, it is not necessary to consider temperature also whencomposing pixel signals of both pixels.

Meanwhile, in the method of providing the large pixel and the smallpixel, both the pixels have different structures. That is, the size ofthe photoelectric conversion unit such as a PD differs between bothpixels, and various characteristics that change depending on temperatureof both pixels differ. Examples of the various characteristics thatchange depending on temperature include sensitivity characteristics,saturation charge amount Qs, conversion efficiency, white spotgeneration characteristics, and black spot generation characteristics.Hereinafter, these are collectively referred to as temperature dependentcharacteristics.

Therefore, in the case where a pixel signal of a large pixel and a pixelsignal of a small pixel are composed, if the above-mentioned temperaturedependent characteristics are not considered, a step occurs at thejunction of the pixel signal of the large pixel and the pixel signal ofthe small pixel depending on temperature or the change in pixel signalwith respect to the change in luminance of an object cannot maintain thelinearity in some cases. In such a case, degradation of image qualitysuch as generation of false color on the generated WD image occurs.

The present technology has been made in view of the above-mentionedcircumstances and it is an object thereof to suppress, where a pixelsignal of a large pixel and a pixel signal of a small pixel are composedto generate a WD image, degradation of image quality of the WD image.

Solution to Problem

An image processing apparatus according to a first aspect of the presenttechnology includes: a first acquisition unit that acquires a firstpixel signal output from a first pixel; a second acquisition unit thatacquires a second pixel signal output from a second pixel having a sizesmaller than that of the first pixel; a temperature detection unit thatdetects temperature; a composition gain determination unit thatdetermines a composition gain corresponding to the detected temperature;and a composition unit that composes the first pixel signal and thesecond pixel signal multiplied by the composition gain.

An image processing method according to a first aspect of the presenttechnology includes: performing, by the image processing apparatus, afirst acquisition step of acquiring a first pixel signal output from afirst pixel; a second acquisition step of acquiring a second pixelsignal output from a second pixel having a size smaller than that of thefirst pixel; a temperature detection step of detecting temperature; acomposition gain determination step of determining a composition gaincorresponding to the detected temperature; and a composition step ofcomposing the first pixel signal and the second pixel signal multipliedby the composition gain.

An electronic apparatus according to a second aspect of the presenttechnology is an electronic apparatus on which a solid-state imagesensor is mounted, the solid-state image sensor including: a pixel unit,a plurality of first pixels and a plurality of second pixels beingarranged in the pixel unit, each of the plurality of second pixelshaving a size smaller than that of each of the plurality of firstpixels; a first acquisition unit that acquires a first pixel signaloutput from the first pixel; a second acquisition unit that acquires asecond pixel signal output from the second pixel; a temperaturedetection unit that detects temperature; a composition gaindetermination unit that determines a composition gain corresponding tothe detected temperature; and a composition unit that composes the firstpixel signal and the second pixel signal multiplied by the compositiongain.

In the first and second aspects of the present technology, a first pixelsignal output from a first pixel is acquired; a second pixel signaloutput from a second pixel having a size smaller than that of the firstpixel is acquired; temperature is detected; a composition gaincorresponding to the detected temperature is determined; and the firstpixel signal and the second pixel signal multiplied by the compositiongain are composed.

Advantageous Effects of Invention

In accordance with the first aspect of the present technology, it ispossible to suppress degradation of image quality of a WD image obtainedby composing a pixel signal of a large pixel and a pixel signal of asmall pixel.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration example of an imageprocessing apparatus to which the present technology is applied.

FIG. 2 is a diagram showing an example of a temperature dependentcorrection amount corresponding to temperature.

FIG. 3 is a flowchart describing WD image generation processing by animage processing apparatus to which the present technology is applied.

FIG. 4 is a diagram showing the results of an existing compositionmethod at 60° C.

FIG. 5 is a diagram showing the results of an existing compositionmethod at 105° C.

FIG. 6 is a diagram showing the results of the WD image generationprocessing at 105° C.

FIG. 7 is a view depicting an example of a schematic configuration of anendoscopic surgery system.

FIG. 8 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

FIG. 9 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 10 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

MODE(S) FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present technology(hereinafter, referred to as embodiment) will be described in detailwith reference to the drawings.

<Configuration Example of Image Processing Apparatus according toEmbodiment of Present Technology>

FIG. 1 is a block diagram showing a configuration example of an imageprocessing apparatus according to an embodiment of the presenttechnology.

The image processing apparatus includes a pixel unit 11, an imagingcontrol unit 12, a temperature detection unit 13, a large-pixel-signalprocessing unit 14, a large-pixel table 15, a small-pixel-signalprocessing unit 16, a small-pixel table 17, a composition gaindetermination unit 18, a composition gain table 19, and a compositionunit 20.

The pixel unit 11 includes a solid-state image sensor such as a CMOSimage sensor in which a large pixel and a small pixel having differentlight reception sensitivities are arranged in accordance with apredetermined rule. Note that the large pixel and the small pixel eachinclude any of color filters of R (red), G (green), and B (blue) or afilter for acquiring a wavelength band other than visible light, andgenerates a pixel signal including a color component of R, G, or B or awavelength band other than visible light. The pixel unit 11 outputs apixel signal of the large pixel to the large-pixel-signal processingunit 14, and a pixel signal of the small pixel to the small-pixel-signalprocessing unit 16. Hereinafter, the pixel signal of the large pixelwill be referred to as large-pixel signal, and the pixel signal of thesmall pixel will be referred to as small-pixel signal.

The imaging control unit 12 controls the operation of the pixel unit 11.In particular, the imaging control unit 12 controls the exposure time ofthe large pixel of the pixel unit 11 and the exposure time of the smallpixel of the pixel unit 11, and notifies the composition gaindetermination unit 18 of each of the exposure times.

The temperature detection unit 13 detects temperature of the pixel unit11, and notifies the large-pixel-signal processing unit 14, thesmall-pixel-signal processing unit 16, and the composition gaindetermination unit 18 of the detected temperature.

The large-pixel-signal processing unit 14 performs predetermined signalprocessing corresponding to temperature on the large-pixel signal inputfrom the pixel unit 11, and outputs, to the composition unit 20, thelarge-pixel signal on which signal processing has been performed.

For example, the large-pixel-signal processing unit 14 acquires, fromthe large-pixel table 15, an OB (optical black) clamp value that changesdepending on the change in temperature, and performs OB clamp processingon the large-pixel signal. Further, for example, the large-pixel-signalprocessing unit 14 acquires, from the large-pixel table 15, the minimumgain corresponding to a saturation signal amount Qs that changesdepending on the change in temperature, and multiplies the large-pixelsignal by the acquired minimum gain.

Further, the large-pixel-signal processing unit 14 notifies thecomposition gain determination unit 18 of the minimum gain as amultiplication target for the large-pixel signal.

In the large-pixel table 15, various temperature dependent parametersbased on 45° C. at which it can be assumed that there is no differencebetween temperature dependent characteristics of the large pixel and thesmall pixel are stored as a table in advance. The various temperaturedependent parameters are used in signal processing by thelarge-pixel-signal processing unit 14. Note that instead of the table,the various temperature dependent parameters may be stored as a functionof temperature.

The small-pixel-signal processing unit 16 performs predetermined signalprocessing corresponding to temperature on the small-pixel signal inputfrom the pixel unit 11, and outputs, to the composition unit 20, thelarge-pixel signal on which the signal processing has been performed.

For example, the small-pixel-signal processing unit 16 acquires, fromthe small-pixel table 17, an OB clamp value that changes depending onthe change in temperature, and perform OB clamp processing on thesmall-pixel signal. Further, for example, the small-pixel-signalprocessing unit 16 acquires, from the small-pixel table 17, the minimumgain corresponding to the saturation signal amount Qs that changesdepending on the change in temperature, and multiplies the small-pixelsignal by the acquired minimum gain.

Further, the small-pixel-signal processing unit 16 notifies thecomposition gain determination unit 18 of the minimum gain as amultiplication target for the small-pixel signal.

In the small-pixel table 17, various temperature dependent parametersbased on 45° C. at which it can be assumed that there is no differencebetween temperature dependent characteristics of the large pixel and thesmall pixel are stored as a table in advance. The various temperaturedependent parameters are used in signal processing by thesmall-pixel-signal processing unit 16. Note that instead of the table,the various temperature dependent parameters may be stored as a functionof temperature.

The composition gain determination unit 18 acquires, from thecomposition gain table 19, a temperature dependent correction amountdifferent for each of color components of R, G, and B corresponding totemperature notified from the temperature detection unit 13. Further,the composition gain determination unit 18 determines the compositiongain for each color component by applying the temperature dependentcorrection amount, the exposure time of each of the large pixel and thesmall pixel notified from the imaging control unit 12, the minimum gainnotified from the large-pixel-signal processing unit 14, the minimumgain notified from the small-pixel-signal processing unit 16, and thecomposition gain at 45° C. held in advance to the following formula (1),and notifies the composition unit 20 of the determined composition gain.Composition gain=composition gain at 45° C.×(exposure time of largepixel/exposure time of small pixel)×(minimum gain of large pixel/minimumgain of large pixel)×temperature dependent correction amount  (1)

In the composition gain table 19, a temperature dependent correctionamount for which an appropriate value corresponding to temperature hasbeen obtained is stored in advance as a table.

FIG. 2 shows an example of the temperature dependent correction amountcorresponding to temperature. The horizontal axis of the figureindicates temperature [° C.], and the vertical axis indicates thecorrection amount. In the figure, the correction amount at 45° C. thatis a reference value is one, and the correction amount is set togradually increase as the temperature rises. On the contrary, thecorrection amount is set to be reduced in the case where the temperaturefalls below 45° C. that is a reference value.

Note that in the case where the exposure time of the large pixel, theexposure time of the small pixel, the minimum gain of the large pixel,and the minimum gain of the large pixel are each a fixed value or avariable that depends on temperature, instead of causing the compositiongain table 19 to hold the temperature dependent correction amountcorresponding to temperature, the composition gain table 19 may becaused to hold a composition gain corresponding to temperaturecalculated in advance.

The composition unit 20 composes the large-pixel signal on whichpredetermined signal processing has been performed and the resultobtained by multiplying the small-pixel signal on which predeterminedsignal processing has been performed by the composition gain to generatea WD image. For example, the WD image is generated by adopting thelarge-pixel signal in the case where luminance of an object is low tolower than the luminance where the large-pixel signal is saturated, andadopting the small-pixel signal multiplied by the composition gain inthe case of luminance equal to or higher than the luminance where thelarge pixel is saturated. Further, for example, a composition rate ofone or less corresponding to luminance is set, and the result obtainedby multiplying the large-pixel signal on which predetermined signalprocessing has been performed by the addition rate, and the resultobtained by multiplying the small-pixel signal on which predeterminedsignal processing has been performed by the composition gain(1-composition rate) are added to generate a WD image.

<WD Image Generation Processing by Image Processing Apparatus accordingto Embodiment of Present Technology>

FIG. 3 is a flowchart describing WD image generation processing by theimage processing apparatus.

In Step S1, the pixel unit 11 performs imaging in accordance withcontrol from the imaging control unit 12, and outputs the large-pixelsignal and the small-pixel signal. The large-pixel signal is acquired bythe large-pixel-signal processing unit 14, and the small-pixel signal isacquired by the small-pixel-signal processing unit 16. In Step S2, thetemperature detection unit 13 detects the temperature of the pixel unit11, and notifies the large-pixel-signal processing unit 14, thesmall-pixel-signal processing unit 16, and the composition gaindetermination unit 18 of the detected temperature.

In Step S3, the large-pixel-signal processing unit 14 performspredetermined signal processing corresponding to temperature on thelarge-pixel signal input from the pixel unit 11, and outputs, to thecomposition unit 20, the large-pixel signal on which signal processinghas been performed. In Step S4, the small-pixel-signal processing unit16 performs predetermined signal processing corresponding to temperatureon the small-pixel signal input from the pixel unit 11, and outputs, tothe composition unit 20, the small-pixel signal on which signalprocessing has been performed.

In Step S5, the composition gain determination unit 18 acquires, fromthe composition gain table 19, the temperature dependent correctionamount corresponding to temperature notified from the temperaturedetection unit 13. Further, the composition gain determination unit 18determines the composition gain by applying the temperature dependentcorrection amount, the exposure time of each of the large pixel and thesmall pixel notified from the imaging control unit 12, the minimum gainnotified from the large-pixel-signal processing unit 14, the minimumgain notified from the small-pixel-signal processing unit 16, and thecomposition gain at 60° C. held in advance to the formula (1), andnotifies the composition unit 20 of the determined composition gain.

In Step S6, the composition unit 20 composes the large-pixel signal onwhich predetermined signal processing has been performed and the resultobtained by multiplying the small-pixel signal on which predeterminedsignal processing has been performed by the composition gain to generatea WD image. In this way, the WD image generation processing is finished.

<Effects of WD Image Generation Processing by Image Processing Apparatusaccording to Embodiment of Present Technology>

The effects of the above-mentioned WD image generation processing willbe described.

FIG. 4 shows the change in luminance of an object and the change inlevel of the pixel signal in the case where the large-pixel signal andthe small-pixel signal are composed at 45° C. that is a reference valueof temperature at which it can be assumed that there is no differencebetween temperature dependent characteristics of the large pixel and thesmall pixel by an existing method that does not consider temperaturedependent characteristics of the large pixel and the small pixel. In thefigure, solid lines RL, GL, and BL respectively indicate R, G, and Bcomponents of the large-pixel signal, and broken lines RS, GS, and BSrespectively indicate R, G, and B components of the small-pixel signalmultiplied by the composition gain.

Note that also in the case where the large-pixel signal and thesmall-pixel signal are composed at 45° C. by the WD image generationprocessing, results similar to those in FIG. 4 are obtained.

That is, the solid line RL and the broken line RS, the solid line GL andthe broken line GS, and the solid line BL and the broken line BS areconnected without any step, and the pixel signal level with respect tothe change in luminance is capable of maintaining linearity.

FIG. 5 shows the change in luminance of an object and the change inlevel of the pixel signal in the case where the large-pixel signal andthe small-pixel signal are composed at 105° C., which greatly exceedsthe reference value 45° C., by an existing method that does not considertemperature dependent characteristics of the large pixel and the smallpixel. In the figure, solid lines RL, GL, and BL respectively solidlines RL, GL, and BL respectively indicate R, G, and B components of thelarge-pixel signal, and broken lines RS, GS, and BS respectivelyindicate R, G, and B components of the small-pixel signal multiplied bythe composition gain.

In the case of 105° C., since a difference occurs between temperaturedependent characteristics of the large pixel and the small pixel, thesolid line RL and the broken line RS, the solid line GL and the brokenline GS, and the solid line BL and the broken line BS are not connectedwell as shown in FIG. 5, and degradation of image quality such asgeneration of false color near the junction occurs.

FIG. 6 shows the change in luminance of an object and the change inlevel of the pixel signal in the case where the large-pixel signal andthe small-pixel signal are composed at 105° C., which greatly exceedsthe reference value 45° C., by the above-mentioned WD compositionprocessing. In the figure, solid lines RL, GL, and BL respectively solidlines RL, GL, and BL respectively indicate R, G, and B components of thelarge-pixel signal, and broken lines RS, GS, and BS respectivelyindicate R, G, and B components of the small-pixel signal multiplied bythe composition gain.

In the case of 105° C., although a difference occurs between temperaturedependent characteristics of the large pixel and the small pixel, sincethe composition gain as a multiplication target of the small-pixelsignal is determined corresponding to temperature, as shown in FIG. 6,the solid line RL and the broken line RS, the solid line GL and thebroken line GS, and the solid line BL and the broken line BS aresmoothly connected as compared with FIG. 5, and the pixel signal levelwith respect to the change in luminance is capable of maintaininglinearity. Therefore, it is possible to suppress degradation of imagequality such as generation of false color near the junction.

Modified Example

In the above description, the pixel unit 11 of the image processingapparatus shown in FIG. 1 has included a solid-state image sensor suchas a CMOS image sensor. However, the solid-state image sensor mayinclude components other than the pixel unit 11 in FIG. 1. That is, thesolid-state image sensor may include all the components shown in FIG. 1.

<Example of Application to Endoscopic Surgery System>

The technology according to the present disclosure (present technology)is applicable to various products. For example, the technology accordingto the present disclosure may be applied to an endoscopic surgerysystem.

FIG. 7 is a view depicting an example of a schematic configuration of anendoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In FIG. 7, a state is illustrated in which a surgeon (medical doctor)11131 is using an endoscopic surgery system 11000 to perform surgery fora patient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy treatment tool11112, a supporting arm apparatus 11120 which supports the endoscope11100 thereon, and a cart 11200 on which various apparatus forendoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody lumen of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which includes as a hard mirror having thelens barrel 11101 of the hard type. However, the endoscope 11100 mayotherwise be included as a soft mirror having the lens barrel 11101 ofthe soft type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel 11101by a light guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body lumen of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a direct view mirror or may be a perspective view mirror ora side view mirror.

An optical system and an image pickup element are provided in the insideof the camera head 11102 such that reflected light (observation light)from the observation target is condensed on the image pickup element bythe optical system. The observation light is photo-electricallyconverted by the image pickup element to generate an electric signalcorresponding to the observation light, namely, an image signalcorresponding to an observation image. The image signal is transmittedas RAW data to a CCU 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or a like to change an image pickup condition (typeof irradiation light, magnification, focal distance or the like) by theendoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy treatment tool 11112 for cautery or incision of a tissue, sealingof a blood vessel or the like. A pneumoperitoneum apparatus 11206 feedsgas into a body lumen of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body lumen in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagepickup elements of the camera head 11102 are controlled in synchronismwith the irradiation timings. Then images individually corresponding tothe R, G and B colors can be also picked up time-divisionally. Accordingto this method, a color image can be obtained even if color filters arenot provided for the image pickup element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the image pickup element of the camerahead 11102 in synchronism with the timing of the change of the intensityof light to acquire images time-divisionally and synthesizing theimages, an image of a high dynamic range free from underexposed blockedup shadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrow band in comparison with irradiation lightupon ordinary observation (namely, white light), narrow band observation(narrow band imaging) of imaging a predetermined tissue such as a bloodvessel of a superficial portion of the mucous membrane or the like in ahigh contrast is performed. Alternatively, in special light observation,fluorescent observation for obtaining an image from fluorescent lightgenerated by irradiation of excitation light may be performed. Influorescent observation, it is possible to perform observation offluorescent light from a body tissue by irradiating excitation light onthe body tissue (autofluorescence observation) or to obtain afluorescent light image by locally injecting a reagent such asindocyanine green (ICG) into a body tissue and irradiating excitationlight corresponding to a fluorescent light wavelength of the reagentupon the body tissue. The light source apparatus 11203 can be configuredto supply such narrow-band light and/or excitation light suitable forspecial light observation as described above.

FIG. 8 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 7.

The camera head 11102 includes a lens unit 11401, an image pickup unit11402, a driving unit 11403, a communication unit 11404 and a camerahead controlling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The image pickup unit 11402 is configured as an image pickup element.The number of image pickup elements which is included by the imagepickup unit 11402 may be one (single-plate type) or a plural number(multi-plate type). Where the image pickup unit 11402 is configured asthat of the multi-plate type, for example, image signals correspondingto respective R, G and B are generated by the image pickup elements, andthe image signals may be synthesized to obtain a color image. The imagepickup unit 11402 may also be configured so as to have a pair of imagepickup elements for acquiring respective image signals for the right eyeand the left eye ready for three dimensional (3D) display. If 3D displayis performed, then the depth of a living body tissue in a surgicalregion can be comprehended more accurately by the surgeon 11131. It isto be noted that, where the image pickup unit 11402 is configured asthat of stereoscopic type, a plurality of systems of lens units 11401are provided corresponding to the individual image pickup elements.

Further, the image pickup unit 11402 may not necessarily be provided onthe camera head 11102. For example, the image pickup unit 11402 may beprovided immediately behind the objective lens in the inside of the lensbarrel 11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the image pickup unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the image pickup unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to image pickupconditions such as, for example, information that a frame rate of apicked up image is designated, information that an exposure value uponimage picking up is designated and/or information that a magnificationand a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be designated bythe user or may be set automatically by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,an auto exposure (AE) function, an auto focus (AF) function and an autowhite balance (AWB) function are incorporated in the endoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy treatmenttool 11112 is used and so forth by detecting the shape, color and soforth of edges of objects included in a picked up image. The controlunit 11413 may cause, when it controls the display apparatus 11202 todisplay a picked up image, various kinds of surgery supportinginformation to be displayed in an overlapping manner with an image ofthe surgical region using a result of the recognition. Where surgerysupporting information is displayed in an overlapping manner andpresented to the surgeon 11131, the burden on the surgeon 11131 can bereduced and the surgeon 11131 can proceed with the surgery withcertainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

An example of the endoscopic surgery system to which the technologyaccording to the present disclosure can be applied has been describedheretofore. The technology according to the present disclosure isapplicable to, for example, the endoscope 11100, (the image pickup unit11402 of) the camera head 11102, and (the image processing unit 11412of) the CCU 11201 among the above-mentioned configurations.

The technology according to the present disclosure (the presenttechnology) is applicable to various products. For example, thetechnology according to the present disclosure may be realized as anapparatus mounted on any type of moving objects such as an automobile,an electric car, a hybrid electric vehicle, a motorcycle, a bicycle,personal mobility, an airplane, a drone, a ship, and a robot.

FIG. 9 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 9, the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 9, anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 10 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 10, the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimages of the front obtained by the imaging sections 12101 and 12105 areused mainly to detect a preceding vehicle, a pedestrian, an obstacle, asignal, a traffic sign, a lane, or the like.

Incidentally, FIG. 10 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

An example of the vehicle control system to which the technologyaccording to the present disclosure can be applied has been describedheretofore. The technology according to the present disclosure isapplicable to, for example, the imaging section 12031 or the like amongthe above-mentioned configurations.

It should be noted that embodiments of the present technology are notlimited to the above-mentioned embodiments and various modifications canbe made without departing from the essence of the present technology.

It should be noted that the present technology may also take thefollowing configurations.

(1)

An image processing apparatus, including:

a first acquisition unit that acquires a first pixel signal output froma first pixel;

a second acquisition unit that acquires a second pixel signal outputfrom a second pixel having a size smaller than that of the first pixel;

a temperature detection unit that detects temperature;

a composition gain determination unit that determines a composition gaincorresponding to the detected temperature; and

a composition unit that composes the first pixel signal and the secondpixel signal multiplied by the composition gain.

(2)

The image processing apparatus according to (1) above, further including

a pixel unit, a plurality of the first pixels and a plurality of thesecond pixels being arranged in the pixel unit.

(3)

The image processing apparatus according to (1) or (2) above, in which

the first pixel and the second pixel have different temperaturedependent characteristics.

(4)

The image processing apparatus according to any one of (1) to (3) above,further including

a table that stores a temperature dependent correction amount inassociation with temperature, in which

the composition gain determination unit acquires, from the table, thetemperature dependent correction amount corresponding to the detectedtemperature, and calculates the composition gain by using the acquiredtemperature dependent correction amount.

(5)

The image processing apparatus according to any one of (1) to (3) above,further including

a table that stores the composition gain in association withtemperature, in which

the composition gain determination unit acquires, from the table, thecomposition gain corresponding to the detected temperature.

(6)

The image processing apparatus according to any one of (1) to (5) above,further including:

a first signal processing unit that performs predetermined signalprocessing on the first pixel signal; and

a second signal processing unit that performs predetermined signalprocessing on the second pixel signal, in which

the composition unit composes the first pixel signal on which thepredetermined signal processing has been performed and the second pixelsignal on which the predetermined signal processing has been performed,the second pixel signal being multiplied by the composition gain.

(7)

The image processing apparatus according to (6) above, in which

at least one of the first signal processing unit or the second signalprocessing unit performs OB (optical black) clamp processingcorresponding to the detected temperature.

(8)

The image processing apparatus according to (6) or (7) above, in which

at least one of the first signal processing unit or the second signalprocessing unit performs processing of multiplying a minimum gaincorresponding to the detected temperature.

(9)

An image processing method for an image processing apparatus, including:

performing, by the image processing apparatus, a first acquisition stepof acquiring a first pixel signal output from a first pixel;

a second acquisition step of acquiring a second pixel signal output froma second pixel having a size smaller than that of the first pixel;

a temperature detection step of detecting temperature;

a composition gain determination step of determining a composition gaincorresponding to the detected temperature; and

a composition step of composing the first pixel signal and the secondpixel signal multiplied by the composition gain.

(10)

An electronic apparatus on which a solid-state image sensor is mounted,the solid-state image sensor including:

a pixel unit, a plurality of first pixels and a plurality of secondpixels being arranged in the pixel unit, each of the plurality of secondpixels having a size smaller than that of each of the plurality of firstpixels;

a first acquisition unit that acquires a first pixel signal output fromthe first pixel;

a second acquisition unit that acquires a second pixel signal outputfrom the second pixel;

a temperature detection unit that detects temperature;

a composition gain determination unit that determines a composition gaincorresponding to the detected temperature; and

a composition unit that composes the first pixel signal and the secondpixel signal multiplied by the composition gain.

REFERENCE SIGNS LIST

-   -   11 pixel unit    -   12 imaging control unit    -   13 temperature detection unit    -   14 large-pixel-signal processing unit    -   15 large-pixel table    -   16 small-pixel-signal processing unit    -   17 small-pixel table    -   18 composition gain determination unit    -   19 composition table    -   20 composition unit

The invention claimed is:
 1. An image processing apparatus, comprising:a central processing unit (CPU) configured to: acquire a first pixelsignal output from a first pixel; acquire a second pixel signal outputfrom a second pixel having a size smaller than that of the first pixel;acquire a temperature of a pixel unit that comprises the first pixel andthe second pixel; determine a composition gain corresponding to theacquired temperature; and compose the first pixel signal, and the secondpixel signal multiplied by the composition gain.
 2. The image processingapparatus according to claim 1, further comprising the pixel unit,wherein the pixel unit further comprises a plurality of first pixels anda plurality of second pixels, the plurality of first pixels includes thefirst pixel, and the plurality of second pixels includes the secondpixel.
 3. The image processing apparatus according to claim 2, whereintemperature dependent characteristics of the first pixel is differentfrom temperature dependent characteristics of the second pixel.
 4. Theimage processing apparatus according to claim 2, further comprising atable that stores a plurality of temperature dependent correctionamounts in association with a plurality of temperatures, wherein the CPUis further configured to: acquire, from the table, a temperaturedependent correction amount corresponding to the acquired temperature,wherein the plurality of temperature dependent correction amountsincludes the acquired temperature dependent correction amount, and theplurality of temperatures includes the acquired temperature; andcalculate the composition gain based on the acquired temperaturedependent correction amount.
 5. The image processing apparatus accordingto claim 2, further comprising a table that stores a plurality ofcomposition qains in association with a plurality of temperatures,wherein the CPU is further configured to acquire, from the table, thecomposition gain corresponding to the acquired temperature, theplurality of composition gains includes the composition gain, and theplurality of temperatures includes the acquired temperature.
 6. Theimage processing apparatus according to claim 2, wherein the CPU isfurther configured to: perform signal processing on the first pixelsignal to generate processed first pixel signal; perform signalprocessing on the second pixel signal to generate processed second pixelsignal; and compose the processed first pixel signal, and the processedsecond pixel signal multiplied by the composition gain.
 7. The imageprocessing apparatus according to claim 6, wherein the CPU is furtherconfigured to perform an OB (optical black) clamp processing operation,corresponding to the acquired temperature, on at least one of the firstpixel signal or the second pixel signal.
 8. The image processingapparatus according to claim 6, wherein the CPU is further configured toperform a multiplying operation of a minimum gain, corresponding to theacquired temperature, and at least one of the first pixel signal or thesecond pixel signal.
 9. An image processing method, comprising: in animage processing apparatus; acquiring a first pixel signal output from afirst pixel; acquiring a second pixel signal output from a second pixelhaving a size smaller than that of the first pixel; acquiring atemperature of a pixel unit that comprises the first pixel and thesecond pixel; determining a composition gain corresponding to theacquired temperature; and composing the first pixel signal, and thesecond pixel signal multiplied by the composition gain.
 10. Anelectronic apparatus comprising: a solid-state image sensor mounted onthe electronic apparatus, wherein the solid-state image sensorcomprises: a pixel unit, wherein the pixel unit comprises a plurality offirst pixels and a plurality of second pixels, and each of the pluralityof second pixels having a size smaller than that of each of theplurality of first pixels; and a central processing unit (CPU)configured to: acquire a first pixel signal output from a first pixel ofthe plurality of first pixels; acquire a second pixel signal output froma second pixel of the plurality of second pixels; acquire a temperatureof the pixel unit; determine a composition gain corresponding to theacquired temperature; and compose the first pixel signal, and the secondpixel signal multiplied by the composition gain.